Attrition mill



April 20 1926.

- I 1,581,969 A. A. LONGAKER ATTRITION MILL Filed April 15, 1925 I5 Sheets-Sheet 1 jm aa wd April 20 1926. 1,581,959

A. A. LONGAKER ATTRITION MILL Filed. April 15, 1925 3 Sheets-Sheet 2 imm- HZZ Z fl mvgpdi n April 20 1926. 1,581,969

A. A. l-QNGAKER ATTRITION MILL Filed April 15 1925 5 Sheets-sheaf 5 Patented Apr. 20, 1926.

IUNITED stares 1,581,969 rArEu-r OFFICE.

ALBERT A. LONGAKER, or CHAMBERSBURG, PENNSYLVANIA, assrcnos TO THE worn COMPANY; or cHnMBERsBUac, PENNSYLVANIA, A conroaArron or PENNSYL- VANIA.

' nrrarrron MILL.

Application filed. April 15, 1925. Serial No. 23,305. d

To all whom it may concern,-

Be it known that I, ALBERT A. LONGAKER, a citizen of the United States, residing in Chambersburg, Pennsylvania, have invented an Attrition Mill, of which the following is a specification.

This invention relates to machines for reducing, grinding or finely dividing material such as grain, corn cobs and the like by cutting, rubbing or attrition. The invention relates particularly to machines oft-he type in which-the attrition is effected between two grinding discs orplates which are pro- .vided with suitable ribs or teeth. In machines of this type, one of the grinding plates is rotated with respect to the other and usually both plates are rotated but in opposite directions. t

The principal object of the invention is to provide in a machine of the type specified,

improved means for supporting the grinding plates and for rotating them in opposite directions. Other objects of the invention will be apparent from the following'specification and claims.

In the accompanying drawings, I have il-.

lustrated the embodiment of the invention which I now deem preferable, but it will he understood that various changes and substitutions may be made within'the scope of the claims forming a part of this specificatioii wit-hout'departing from the spirit of the invention. Of the drawings:

Fig. l is a front elevation;

Fig. 2 is a vertical sectional view;-

Fig. 3 is a horizontal sectional view taken along the line 3-3 of Fig. 2.

In the drawings, I have shown a machine of the type whereinthe grinding plates are horizontal and are rotatable about a vertical axis. As concerns certain phases of the in vention, however, I do not limit myself to a machine of this type. As illustrated, there is a main frame or casing comprising a lower section 1. mounted on a base'2 and an upper section 3' suitably connectedwith the lower section 1. Mounted in the casing for rotation about a vertical axis is a spiderfi having an upper hollow trunnion 6 and a lower hollow trunnion 7. These trunnions are respectively carried by bearings 8 and 9, the bearing 8 being supported at the top of the upper part- 3 of the casing andthe bearing 9 being supported by a rib or web extending across the lower part 1 of the casing. Preferablythesebearings 8 and 9 are combination bearings for taking both radial and axial loads and as shown they are of the tapered roller type. In order to take up any end-play in the bearings, one of them is axially adjustable, and I have indicated the upper bearing 8 as being adjustable by means of the nuts, 10 on the studs 11.

Preferably inorderto prevent any oil or other lubricant' from flowing down into the grinding chamber, a suitable stufling box is provided at 12 below the'upper bearing 8.

The spider 5 comprises a top plate 13 preferably formed integrally with the trunnion G'and also a plurality of arms 14 radiating from ahub 15. bolted to a flange 16 on the trunnion 7;

As shown, thishub is Preferably there is a ring 18-formed integrally with the arms 14: and bolts 19-19 extending through the ring serve to connect the two parts of the spider together. The upper grinding plate 20 is detachably con- Iiected with the plate 13 by means of suitable bolts and'the lower grinding plate 21 is supported in opposed relationship to the plate 20 by means of a bar or shaft 22. This baror, shaft 22 extends through the hollow trunnion 7 and preferably isso mounted that it can be rotated separately from the trunnion and fromthe spider. I

As illustrated, the shaft 22 is supported by bearings 23 and 24. The bearing 23 is interposed between the shaft and thehub ,15 of the spider there preferably being a sleeve 25 which has a splined connection with the shaft to permit the shaft to'be adjusted longitudinally. The bearing 24 for the shaft is at the lower end thereof and is preferably so mounted that it can be bodily raisedor lowered in a manner to be hereinafter de scribed. Preferably and as shown, the two bearings 23 and 24 are adapted tocarry both radial and axial loads and are of the tapered roller type. In order to keep the material which is being ground from entering the upper bearing 23, thereis preferably pro vided a suitable stuffing box 26.

Suitable mechanism is provided for driving the lower trunnion 7 and thereby driving the spider and the upper grindin plate 20. Preferably the lower grinding p ate 21 is also driven but in the opposite direction through the shaft As a convenient means for driving these two elements in opposite directions, I provide two driven bevel gears 27 and 28, both meshing with a common driving bevel gear 29. Preferably in order to secure a smooth drive and to avoid any unnecessary noise. the gears are of the spiral bevel type. The upper bevel gear 27 is rigidly keyed or otherwise secured'to the'trunnion 7. The lower bevel gear 28 is so connected with the shaft 22 as to permit the shaft to be freely adjusted through it. As shown, the lower end of the shaft is square and extends through a square hole in a bushing 30 secured to the gear 28. The gear 28 is provided with a bearing 31 whereby it is supported without dependence being placed on the shaft 22. A plain thrust bearing 31 is also provided to prevent any tendency of the gear to move upward. It will be noted that the beforementioned bearing 9 is so located that it lies in the space between the two bevel gears 27 and 28. This enables the bearing to support the trunnion 7 at its extreme lower end and thus insure proper meshing of the gear 27 with the gear 2.9.

The driving bevel gear 29 is mounted on a drive shaft 32 which extends out through the side of the machine and receives power from any suitable source such as a belt pulley or an electric motor. Preferable provision is made whereby the machine can be driven in either direction. This is desirable in order to equalize wear on the attrition plates. The shaft 32 is carried by bearings 33 and 34 preferably of the tapered roller type. As shown both of the bearings 33 and 34 are carried in a housing 35 which extends through a relatively large hole in the side of the casing and is held in place by bolts 36. The hole in the casing is large enough to permit the bevel gear 29 to be removed therethrough and it istherefore possible by loosening the bolts 36 to remove the housing 35 and all of the parts carriedthereby without disassembling them. Preferably as shown, the two bearings 33 and 34 are adjustable axially with respect to the housing 35 by means of the bolts 37 and 38 respectively. This construction makes it possible for the entire shaft with the bevel gear to be shifted axially so as to effect proper meshing of the gears and it also permits proper relative adjustment between the bearings to take up any lost motion.

The material to be ground is introduced to the plates 20 and 21 through the hollow trunnion 6 and preferably there is provided at the top of the machine a suitable feeding device 39. This constitutes no part of my present invention and will not therefore be described in detail. It is suiiicient to say that it includes a hopper 4-0 and a rotatable drive shaft ll driven by means of a belt from the main shaft 32. The material thus introduced passes radially outward between the two plates, and is suitably ground or co-mminuted and passes into the chamber in the upper section 3 of the casing. In order to prevent the ground material from passing downward into the lower chamber where the driving mechanism is located, a partition is provided in the form of a plate 43.

The material passes out of the casing through a discharge out-let 44. into a conveyer or into any suitable receptacle. Preferably this discharge outlet 14 is located at the rear of the machine as shown in Fig. 3. The rotating arms 14 of the spider carry the material to the discharge outlet and in order that they may operate more effectively for this purpose, they are preferably provided with vanes -15 which prevent any considerable accumulation of ground material at the edges of the chamber. I Preferably the upper section 3 of the casing is made in two parts. the front part 3 being pivoted at 3 to the rear part which is fixed. It will be understood that the upper bearing 8 is mounted on the fixed part of the casing. so that it is not disturbed when the pivoted part is swung forward.

As already stated, the bearing 2t is vertically adjustable for the purpose of vertically adjusting the shaft 22 and the grinding plate 21. The details of the mechanism for effecting this adjustment form no part of my present invention, but I prefer and have shown a mechanism in which the bear ing 24 rests upon a shoe 16 which is engaged by a lever 47 horizontally pivoted between its ends at 18. The other end of the lever 17 is engaged by a suitable adjusting means which is shown as being a rotatable screw 49 extending through a nut 50 which is held against rotation by a pin 50. The screw is rotatable by means of a hand wheel 51. It will be seen that by rotating the hand wheel, the lever 17 may be rocked thereby raising or lowering the shaft 22 and the plate 21. In this way, the plates can be adjusted to the proper relation for securing the desired results in grinding.

The nut 50 is so mounted that it can moveupward against the resistance of a spring 52. The spring normally serves to hold the nut in its lower position as shown but will permit it to rise when abnormal grinding conditions are encountered. The lower position of the nut is determined by a flange on a sleeve 53 having threaded engagement with a casing 5-1 which surrounds and supports the spring. By turning the sleeve with relation to the casing 54, the tension of the spring can be changed to suit different conditions. It will be understood that any adjustment of 'the sleeve 53 will. initially change the adjustment of the plate 21, but any movement of the sleeve 53 can be compensated for by a corresponding adjustment of the screw 49.

It" is frequently desirable to separate the plates 20 and 21 temporarily, and in order that this can be done readily without disturbing the 'normaladjustment which has been secured by meansof the screw 49 and the hand wheel 51,. the casing 54 is adapted to be rotated through a limitedwangle by means of a'handle 55. The upper end of the casing is provided with a helical cam surface 56 which is adapted to engage a similar helical'cam surface 57 formed on the lower side of a supporting bracket 58. When the casing is adjusted to the position shown in Fig. 2, the plate 21 is in normal working the plates, bearings for the trunnions, a supporting member for the other plate. extending through the other trunnion, and means engaging the last said trunnion for rotating the spider separately from the supporting member. i

2. An attrition mill comprising in combination, two opposedattrition plates, a ro tatable spider-carryingone of the plates having two hollow axial trunnions on oppm site sides of the plates, one ofthe trunnions serving for the supply of raw material to the plates, bearings for the trunn ons, a supporting member for the other plate extending through the other trunnion, means engaging the last said trunnion-for rotating the spider separately from the supporting member, and means for adjusting the supporting member axially with respect to the spider for changing the distance between the plates. Y r

3. An attrition mill comprising in combination, two opposed attrition plates, a'rotatable spider carrying one of the plates and having two hollow axial trunnions on opposite sides, of the plates, one of the trunnions serving for the supply of raw material to the plates, bearings for the trunnions, a supportmg shaft for the other plate extending through the other trunnion, and mechanism engaging the last said trunnion and the said shaft forrotating them in opposite directions.

4:. An attrition mill comprising in combination, two opposed horizontal attrition plates, a rotatable'spider carrying the up per plate and having two hollow vertical trunnions respectively above and below the plates, the upper trunnion serving for the supply of raw material to the plates, bearings forthe trunnions, a supporting shaft 'forthe lowertplate extending through t-l e lower trunnion, and mechanism engaging the lower trunnion andrthe shaft or rotating themvin opposite. directions.

5. An attrition mill comprising nation, two opposed horizontal attrition plates, a rotatable spider carrying the upper :plate andhaving two hollow vertical, trunnions respectively above and below the plates, theupper trunnionserving for the supply of raw material to the plates, bearings forthe trunnions, asupporting shaft for the lower plate extending through the lower trunnion, mechanism engaging the lower trunnion and the shaft for rotating them in opposite direct-ions, and means for adjusting'the shaft vertically with respect to the spider for changing the distance between plates.

6. An attrition mill comprising in combi" nation, two opposed horizontal attrition plates, a rotatable spider carrying the upper plate and having two hollow vertical trunnions respectively above and below the plates, the upper trunnionserving for the supply. of raw material to the plates, bearings for the trunnions, a. supporting shaft for the lower platerextending through the lower trunnion, an anti-friction hearing between the shat't and the upper end of the lower trunnion, and mechanism engaging the lower trunnion and the shaft for rotating them in opposite directions.

- ,7'. An attrition mill comprising in combi nation, two vopposed horizontal attrition plates, a rotatable spider carrying the upper plate and having two hollow vertical trunnions respectively above and below the plates, the upper trunnion. serving for the supply of raw material to the plates, combination anti-friction bearings for both radial and opposed thrust loads engaging the two trunnions near their respective upper and lower ends, means for adjustingthe outer races of the bearings axially to avoid and take up lost motion, a supporting shaft for the lower plate extending through the lower trunnion, and mechanism engaging the lower trunnion and the shaft for rotating them in opposite directions.

8. An attrition mill comprising in combination, two opposed horizontal attrition plates, a rotatable spider carrying the upper plate and having two hollow vertical trunnions respectively above and below the plates, the upper trunnion serving for the supply of raw material to the plates, a supporting shaft for the lower plate extending through the lower trunnion, two driven bevel gears connected respectively with the lower trunnionand with the projecting end of the shaft, a drivingbevel gear meshing in combiwith both of the said driven gears to rotate them in opposite directions, and bearings for the said trunnions, that for the lower trunnion being located at the end thereof between the two driven bevel gears.

9. An attrition mill comprising in combination, a main frame or casing, two opposed horizontal attrition plates, a rotatable spider carrying the upper plate and having two hollow vertical trunnions respectively above and below the plates, the upper trunnion servingfor the supply of raw material to the plates, a supporting shaft for the lower plate extending through the lower trunnion, two bearings carried by the main frame and supporting the two trunnions respectively, two other bearings located respectively below the first said bearings and supporting the shaft, one of the last said bearings being carried by the lower trunnion and the other by the main frame, and mechanism engaging the lower trunnion and the shaft for rotating them in opposite directions.

10. The combination of two opposed horizontal attrition plates, a spider rotatable about a vertical axis and carrying one of the said plates, a shaft rotatable concentrically with the spider and carrying the other plate, means for adjusting the shaft axially with respect to the spider for changing the distance between the plates, two driven bevel gears of which the upper is connected with the spider and the lower is slidably connected with the shaft to permit the aforesaid adjustment, a driving bevel gear meshing with both of the said driven gears to rotate them in opposite directions, and two independent bearings for the lower driven bevel gear and for the lower end of the shaft respectively.

7 11. The combination'of two opposed horizontal attrition plates, a spider rotatable about a vertical axis and carrying one of the said plates, a shaft rotatable concentrically with the spider and carrying the other plate, two driven bevel gears of which the upper is connected with the spider and the lower is slidably connected with the shaft, a driving bevel gear meshing with both of the said driven gears to rotate them in opposite directions, two independent bearings for the lower driven bevel gear and for the lower end of the shaft respectively, and means for bodily n'ioving the last said bearing for the shaft independently of the bearing for the bevel gear for moving the shaft and thereby changing the distance between the plates.

12. In an attrition mill, the combination f a main casing having upper and lower chambers with a partition between, a rotatable spider located in the upper chamber and having a hollow trunnion extending downward through the partition, a shaft extending through the trunnion, opposed hori zontal attrition plates carried by the spider and by the shaft respectively, two driven bevel gears in the lower chamber of which one is connected with the trunnion and the other with the shaft, a driving bevel gear meshing with both of the said driven gears to rotate them in opposite directions, a horizontal driving shaft for the last said gear, an'l a housing carrying the said shaft and extending through an opening into the lower chamber, the said housing and the said opening being large enough to permit the gear to be withdrawn from the lower chamber when the housing is removed.

13. In an attrition mill, the combination of a main casing having upper and lower chambers with a partition between, the said upper chamber having an inlet opening at the top and an outlet opening at one side, a rotatable spider located in the upper chamber and having a hollow trunnion extending downward through the partition, a shaft extending through the trunnion, opposed horizontal attrition plates of which the upper is carried by the spider and the lower by the shaft, means for rotating the spider and shaft in opposite directions, and vanes carried by the spider below the lower attrition plate for sweeping ground material toward the outlet opening and for preventing any considerable amount thereof from accumulating in the chamber.

ALBERT A. LONGAKER. 

